In general, as shown in FIG. 1, a direct-drive type washing machine is configured to include: a casing 100 forming an external appearance; a washing tub 102 that is supported in the inside of the casing 100 and that accommodates water; a dehydrating tub 104 that is rotatably arranged in the inside of the washing tub 102, to perform washing and dehydration; a pulsator 106 that is secured on the bottom of the dehydrating tub 104 to form a washing stream of water; and a driving apparatus 110 that is arranged on the lower portion of the casing 100 to drive the dehydrating tub 104 and the pulsator 106.
A conventional driving apparatus 110 for the direct-drive type washing machine is configured to include: a dehydrating tub rotating shaft 114 that is connected with the dehydrating tub 104 to rotate the dehydrating tub 104 and is formed in a hollow form; a pulsator rotating shaft 112 that is connected with the pulsator 106 to rotate the pulsator 106 and that is arranged in a mutually concentric form in the inside of the dehydrating tub rotating shaft 114; a clutch device 130 that controls rotations of the dehydrating tub rotating shaft 114 and the pulsator rotating shaft 112, during performing washing or dehydration; a drive motor 150 that generates torque of the dehydrating tub rotating shaft 114 and the pulsator rotating shaft 112; and a clutch actuator 140 controlling operation of the clutch device 130.
The function and operation of the conventional direct-drive type washing machine as constructed above will follow.
At a washing cycle, water is supplied to the inside of the washing tub 102, and if the drive motor 150 is driven, the pulsator rotating shaft 112 is rotated, and the pulsator 106 is rotated, to thus form a stream of water in the dehydrating tub 104 in order to wash laundry. Here, the dehydrating tub rotating shaft 114 is constrained by the clutch device 130 and thus is not rotated.
If washing is completed, a water drain pump is driven to perform drainage of water, and the dehydrating tub 104 and the pulsator 106 are rotated at the same time, rinsing and dehydration is repeatedly carried out.
Here, in the case that the dehydrating tub 104 is made to rotate, the clutch actuator 140 is activated and then the clutch device 130 is actuated, to thus deliver the torque of the drive motor 150 to both the dehydrating tub rotating shaft 114 and the pulsator rotating shaft 112 at the same time.
However, the conventional direct-drive type washing machine needs a clutch and a clutch actuator for activating the clutch, in order to deliver the torque of the drive motor 150 to both or one of the dehydrating tub rotating shaft 114 and the pulsator rotating shaft 112, to thereby cause manufacturing costs to be increased and the structure to be complicated.
In addition, in the case of the conventional direct-drive type washing machine, the pulsator and the dehydrating tub are not rotated in the respectively different directions, to thus cause the poor performance of the washing machine.
Korea Patent Registration No. 10-0438616 discloses a conventional direct-drive type washing machine having a clutch in order to rotate only a pulsator, or to rotate both a pulsator and a dehydrating tub, by using a single motor for the washing machine.
The clutch delivers torque of the motor for the washing machine to the pulsator rotating shaft, to thus rotate the pulsator, or delivers the torque of the motor for the washing machine to both the pulsator rotating shaft and the dehydrating tub rotating shaft, to thus rotate both the pulsator and the dehydrating tub simultaneously at high-speed.
However, the clutch includes a coupling, a coupling lifting lever, and a lifting lever driver, and also includes a torque transmission unit having a sun gear, a planetary gear, and a carrier, in order to deliver torque of the rotor to the pulsator during washing, to thus cause a very complex configuration and an expensive manufacturing cost.